Airspeed/ground speed question

[fudge80]

More of a hypothetical than anything and I think I know the answer but thought it would be interesting to discuss.

You are flying a plane that flies at 125kias, no wind at all so groundspeed is the same 125 kph.

Now the same plane manages to get into a 125 knot direct tailwind, what would the airspeed indicator read and what would approximate ground speed be?

Now with a 125 knot direct headwind?

 

[mjburian]

Groundspeed = airspeed +/- tail/head wind

So, for your first question, groundspeed = 250 knots. And groundspeed = 0 knots for the second question. In both cases, 125 knots would be indicated.

You can (and I have) fly a plane "backwards" if you have a strong enough headwind.

 

[fiveoboy01]

What Marty said.

 

[rk911]

Groundspeed = airspeed +/- tail/head wind

So, for your first question, groundspeed = 250 knots. And groundspeed = 0 knots for the second question. In both cases, 125 knots would be indicated.

You can (and I have) fly a plane "backwards" if you have a strong enough headwind.

haven't gone backards but I have hovered...very cool.

 

[genna]

Yep. Airspeed -/+ wind speed = ground speed. Except the airspeed is TAS, not IAS and "kph" is kilometer per hour., not knot

 

[Mason]

Yup.

 

[Stewartb]

Better yet, build a plane that'll fly at 15mph and land it in 15mph wind.